你要了解的springboot拦截器使用

r囧r小猫 2023-10-07 12:34 12阅读 0赞

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NxTDUyMGxU_size_16_color_FFFFFF_t_70]

### Springboottest6Application主启动类 ###

@SpringBootApplication
    @ServletComponentScan   //能够扫描到项目中的Servlet
    public class Springboottest6Application {
        
    	public static void main(String[] args) {
        
    		SpringApplication.run(Springboottest6Application.class, args);	
    	}
    		//创建一个bean
    		@Bean
    		public  ServletRegistrationBean getBean() {
        	
    		   ServletRegistrationBean   bean=new ServletRegistrationBean(new IndexServlet()); 
    		   bean.addUrlMappings("/index.html");
    		   return bean;	
    	       }
    		
    //		@Bean
    //		public FilterRegistrationBean getFilter() {
        
    //			FilterRegistrationBean   bean=new FilterRegistrationBean(new MyFilter());
    //			bean.addUrlPatterns("/index.html");
    //			
    //			return bean;
    //			
    //		}
    		
    		
    		
       }

### MyFilter类 ###

/**
     * 定义一个拦截器
     * @author 戴尔
     *
     */
    //@WebFilter(filterName="MyFilter", urlPatterns="/index.html")
    public class MyFilter implements Filter{
        
    	@Override
    	public void init(FilterConfig filterConfig) throws ServletException {
        
    
    	}
    	@Override
    	public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
    			throws IOException, ServletException {
        
    			//如果你符合我的相关的拦截操作，我会放你过去，否则拦截
    			System.out.println("进入了拦截器");
    			//放行方法
    			chain.doFilter(request, response);		
    			System.out.println("从拦截器出去了");	
    	}
    	@Override
    	public void destroy() {
        
    		// TODO Auto-generated method stub	
    	}
    }

### IndexServlet类 ###

@SuppressWarnings("serial")
    @WebServlet("/index.html")
    public class IndexServlet  extends HttpServlet{
        
    	@Override
    	protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        
    		System.out.println("访问到了我的Get方法");
    		
    		
    	}
    
    }

**成功拦截**  
![在这里插入图片描述][20200414091328142.png]  
创建Bean包也能成功拦截访问  
但是就要注释掉 **主启动类的**//@ServletComponentScan //能够扫描到项目中的Servlet  
也要注释掉**MyFilter类**//@WebFilter(filterName=“MyFilter”, urlPatterns="/index.html")

//创建一个bean
    		@Bean
    		public  ServletRegistrationBean getBean() {
        	
    		ServletRegistrationBean   bean=new ServletRegistrationBean(new IndexServlet()); 
    		   bean.addUrlMappings("/index.html");
    		   return bean;	
    	       }

**bean.addUrlMappings("/\*")**;变成全局多拦截一次 效率变低！！！

在Filter里面加入HttpServletRequest 查看进去拦截的地址\*\*/favicon.ico\*\* (是springboot叶子图标！)

@Override
    	public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
    			throws IOException, ServletException {
        
    		
    		HttpServletRequest req=(HttpServletRequest) request;
    		String url=req.getRequestURI();
    		System.out.println(url);
    			//如果你符合我的相关的拦截操作，我会放你过去，否则拦截
    			System.out.println("进入了拦截器");
    			//放行方法
    			chain.doFilter(request, response);		
    			System.out.println("从拦截器出去了");	
    	}

进入了拦截器
    访问到了我的Get方法
    从拦截器出去了
    进入了拦截器
    从拦截器出去了
    
    查看地址以后！！！结果
    /index.html
    进入了拦截器
    访问到了我的Get方法
    从拦截器出去了
    
    /favicon.ico
    进入了拦截器
    从拦截器出去了

过滤掉！！！图标

HttpServletRequest req=(HttpServletRequest) request;
    		String url=req.getRequestURI();  //打印你所有的请求地址
    //		System.out.println(url);
    		if (url.contains("favicon.ico")) {
        //如果url地址包含/favicon.ico地址就没必要拦截  没必要拦截  也就是勺过滤一次
    			return ;	
    		}

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NxTDUyMGxU_size_16_color_FFFFFF_t_70]: https://img-blog.csdnimg.cn/20200414090930661.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NxTDUyMGxU,size_16,color_FFFFFF,t_70
[20200414091328142.png]: https://img-blog.csdnimg.cn/20200414091328142.png